Mostrar mayor de los cuatro números introducidos y también el menor.

  c
#include <stdio.h>
#include <stdlib.h>

/*
 * 
 */
int main(int argc, char** argv) {
    int A = 10;
    int B = 11;
    int C = 9;
    int D = 0;
    int mayor;
    int menor;

    if (A < B && A < C && A < D) {
        menor = A;

    } else if (A > B && A > C && A > C) {
        mayor = A;
    }

    else if (B < A && B < C && B < D) {
        menor = B;

    } else if (B > A && B > C && B > D) {
        mayor = B;
    }

    else if (C < A && C < B && C < D) {
        menor = C;

    } else if (C > A && C > B && C > D) {
        mayor = C;
    }

    else if (D < A && D < B && D < C) {
        menor = D;
    } else if (D > A && D > B && D > C) {
        mayor = D;

    }
    printf("mayor %d el menor es %d", mayor, menor);
    //return (EXIT_SUCCESS);
}